unified edge rendering for triangle and poly meshes refs #2029

git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free@18323 383ad7c9-94d9-4d36-a494-682f7c89f535

Shaders/Wireframe/fragment_hidden.tpl

-// template file for shader generator
+// hiddenline shader for tri meshes
 
-in vec3 outGeometryBary;
+in float outGeometryHidden;
 
-uniform float lineWidth;
 uniform vec4 bkColor;
 
-float edgeFactor()
-{
-  // compute smoothed distance to edge, source:
-  // http://codeflow.org/entries/2012/aug/02/easy-wireframe-display-with-barycentric-coordinates/
-  
-  vec3 d = fwidth(outGeometryBary);
-  vec3 a3 = smoothstep(vec3(0.0), d*lineWidth, outGeometryBary);
-  return min(min(a3.x, a3.y), a3.z);
-}
-
 void main()
 {
   SG_FRAGMENT_BEGIN
 
-  sg_cColor.xyz = mix(bkColor.xyz, sg_cColor.xyz, 1-edgeFactor());
-    
+  sg_cColor.xyz = mix(sg_cColor.xyz, bkColor.xyz, outGeometryHidden);
+  
   SG_FRAGMENT_END
 }
\ No newline at end of file

Shaders/Wireframe/fragment_hidden_bary.tpl

+// template file for shader generator
+
+in vec3 outGeometryBary;
+
+uniform float lineWidth;
+uniform vec4 bkColor;
+
+float edgeFactor()
+{
+  // compute smoothed distance to edge, source:
+  // http://codeflow.org/entries/2012/aug/02/easy-wireframe-display-with-barycentric-coordinates/
+  
+  vec3 d = fwidth(outGeometryBary);
+  vec3 a3 = smoothstep(vec3(0.0), d*lineWidth, outGeometryBary);
+  return min(min(a3.x, a3.y), a3.z);
+}
+
+void main()
+{
+  SG_FRAGMENT_BEGIN
+
+  sg_cColor.xyz = mix(bkColor, sg_cColor.xyz, 1-edgeFactor());
+    
+  SG_FRAGMENT_END
+}
\ No newline at end of file

Shaders/Wireframe/fragment_wire.tpl

 // template file for shader generator
 
-in vec3 outGeometryBary;
-
-uniform float lineWidth;
-
-float edgeFactor()
-{
-  // compute smoothed distance to edge, source:
-  // http://codeflow.org/entries/2012/aug/02/easy-wireframe-display-with-barycentric-coordinates/
-  
-  vec3 d = fwidth(outGeometryBary);
-  vec3 a3 = smoothstep(vec3(0.0), d*lineWidth, outGeometryBary);
-  return min(min(a3.x, a3.y), a3.z);
-}
-
 void main()
 {
   SG_FRAGMENT_BEGIN
-    
-  float t = 1-edgeFactor();
 
-  // use alpha blending to fade out
-  sg_cColor.a = t;
   
-  // without alpha blending:
-//  sg_cColor.xyz *= t; //mix(vec3(0.0), sg_cColor.xyz, t);
-
-  // discard pixels inside face
-  if (t < 0.1)
-    discard;
-    
+  
   SG_FRAGMENT_END
 }
\ No newline at end of file

Shaders/Wireframe/fragment.tpl → Shaders/Wireframe/fragment_wire_bary.tpl

@@ -26,9 +26,14 @@ void main()
   // without alpha blending:
 //  sg_cColor.xyz *= t; //mix(vec3(0.0), sg_cColor.xyz, t);
 
+  gl_FragDepth = gl_FragCoord.z;
+
   // discard pixels inside face
   if (t < 0.1)
-    discard;
-    
-  SG_FRAGMENT_END
+  {
+    gl_FragDepth = 1.0;
+//    discard; // depth write after discard might depend on gpu driver
+  }
+  
+  SG_FRAGMENT_END  
 }
\ No newline at end of file

Shaders/Wireframe/geometry_hidden.tpl

-// template file for shader generator
+// hiddenline shader for tri meshes
+// emits screen quads for edges
+// emits hidden triangle to update depth buffer
+
+#include "createEdgeQuad.glsl"
 
 layout(triangles) in;
-layout(triangle_strip, max_vertices = 3) out;
+layout(triangle_strip, max_vertices = 15) out;
+
+uniform float lineWidth;
+uniform vec2 screenSize;
 
-// send barycentric coords to fragment
-out vec3 outGeometryBary;
+out float outGeometryHidden;
 
 void main()
 {
+  // draw hidden triangle with background color
+  outGeometryHidden = 1.0;
 
-  sg_MapIO(0); // IO mapping provided by ShaderGen, send vertex 0
-  outGeometryBary = vec3(1, 0, 0);
+  sg_MapIO(0);
   EmitVertex();
-  
-  sg_MapIO(1); // IO mapping provided by ShaderGen, send vertex 1
-  outGeometryBary = vec3(0, 1, 0);
+  sg_MapIO(1);
   EmitVertex();
-  
-  sg_MapIO(2); // IO mapping provided by ShaderGen, send vertex 2
-  outGeometryBary = vec3(0, 0, 1);
+  sg_MapIO(2);
   EmitVertex();
-  
   EndPrimitive();
+
+  // draw edges
+  outGeometryHidden = 0.0;
+
+  createEdgeQuad(0,1, screenSize, lineWidth);
+  createEdgeQuad(1,2, screenSize, lineWidth);
+  createEdgeQuad(2,0, screenSize, lineWidth);
 }
\ No newline at end of file

Shaders/Wireframe/geometry_npoly_hidden.tpl

 // modified hiddenline shader that works for n-poly faces
 
+#include "createEdgeQuad.glsl"
+
 layout(triangles) in;
 layout(triangle_strip, max_vertices = 15) out;
 
@@ -12,8 +14,6 @@ uniform vec2 screenSize;
 
 out float outGeometryHidden;
 
-#include "createEdgeQuad.glsl"
-
 void main()
 {
   int polyEdge = int(texelFetch(polyEdgeBuffer, gl_PrimitiveIDIn/2).x);

Shaders/Wireframe/geometry_wire.tpl

-// template file for shader generator
+// wireframe shader for tri meshes
+// emits screen quads for edges
 
 layout(triangles) in;
-layout(triangle_strip, max_vertices = 3) out;
+layout(triangle_strip, max_vertices = 12) out;
 
-// send barycentric coords to fragment
-out vec3 outGeometryBary;
+uniform float lineWidth;
+uniform vec2 screenSize;
+
+#include "createEdgeQuad.glsl"
 
 void main()
 {
-
-  sg_MapIO(0); // IO mapping provided by ShaderGen, send vertex 0
-  outGeometryBary = vec3(1, 0, 0);
-  EmitVertex();
-  
-  sg_MapIO(1); // IO mapping provided by ShaderGen, send vertex 1
-  outGeometryBary = vec3(0, 1, 0);
-  EmitVertex();
-  
-  sg_MapIO(2); // IO mapping provided by ShaderGen, send vertex 2
-  outGeometryBary = vec3(0, 0, 1);
-  EmitVertex();
-  
-  EndPrimitive();
-}
\ No newline at end of file
+  createEdgeQuad(0,1, screenSize, lineWidth);
+  createEdgeQuad(1,2, screenSize, lineWidth);
+  createEdgeQuad(2,0, screenSize, lineWidth);
+}